Dr. Horace Smith will use this grant to study variable stars in a specific area of the Small Magellanic Cloud (SMC). One hundred and one previously known variables and two hundred and five newly discovered, suspected variables will be included in this survey. This will not only be one of the most extensive studies of SMC variables to date in terms of the number of stars studied, but it will extend fainter than almost all other investigations of SMC field variable stars. For the first time the period-luminosity relations and period-frequency histogram of the faintest SMC Cepheid stars will be established. Questions relating to the nature and distribution of SMC RR Lyrae stars will also be explored. Cepheid stars in the Magellanic Clouds played a significant role in the discovery of the period-luminosity relation. They also helped outline the structure of the Magellanic Clouds, and they have served to test both stellar pulsation theory and stellar evolution theory. For these reasons the Magellanic Cloud Cepheids have been favorite targets of observers. Dr. Smith's study will expand the data base on SMC Cepheids and RR Lyraes to better understand their nature, evolution, and distribution.
